iOS: Many mobile apps promise to find the cheapest gas station in your area, but only SmartFuel helps you find the most affordable fuel while simultaneously ranking nearby gas stations in order of cleanliness and safety.

Smartfuel will find gas stations along your route or near your location and display the most affordable ones so you don't need to drive off-route to find cheap fuel. Once you've selected a station, Smartfuel will provide in-app turn-by-turn directions to get there.

The app also shows a one-to-five star rating for the station's cleanliness and safety based on input from the community. You can post your own rating as well. Smartfuel gets price information from the Oil Price Infromation Service (OPIS) and keeps prices updated in real time. The app offers a 30-day free trial to see if you like it, but after that you'll need to buy a $4.99/6-month, $8.99/year, or $14.99/2-year subscription to continue using it.